Teledesic LLC

Social Fabric Corporation

Moshe L Liron

David Palmer Patterson

Mark Alan Sturza

James R Stuart

Douglas Gene Lockie

Edward F Tuck

Alison K Brown

Vilnis G Grencions

Asu Ram Jha

Donald A Ashford

H Beat Wackernagel, Deceased

A communication system ( ) is disclosed which provides two-way communications access to a wide area network (WAN)( ) for a very large number of subscribers ( ). It offers an inexpensive &ldquo;last-mile&rdquo; hookup from a subscriber terminal ( ) to a communications hub ( ). The hub ( ) is connected to a WAN ( ) such as the Internet. The system comprises service areas ( ), 0.7 to 1.5 km radius ( ), wherein the hub ( ) and subscribers ( ) are located. Subscribers ( ) are connected to a subscriber terminal ( ), directly or through a local area network (LAN)( ). Each terminal ( ) communicates with the hub by a SHF radio link ( ). Distributed routing of signals provides subscribers ( ) with no-waiting, transmission of information at speeds about ten Mbps. Availability of a communication path approximates a fiber optic cable. The LAN ( ) may be a local public switched telephone network. Each service area ( ) is divided into one to forty sectors ( ). Eight sectors ( ) can support approximately 1,600 subscribers ( ). Service areas ( ) may be arranged to cover larger areas. Overlapping service areas ( ) permit subscribers ( ) to be within line-of-sight of a hub ( ). Service area arrangement is readily adapted to terrain, existing structure and number of subscribers ( ).

Network access communication system

The Satellite Communication System disclosed in the specification is a dynamic constellation (C) of satellites (S). The present invention is capable of offering continuous voice, data and video service to customers across the globe on the land, on the sea, or in the air. The preferred embodiment of the invention comprises a low Earth orbit satellite system that includes 40 spacecraft (S) traveling in each of 21 orbital planes at an altitude of 700 km (435 miles). This relatively large number of satellites employed by the preferred embodiment was selected to provide continuous coverage of the Earth's surface at a high minimum mask angle (1230a) of forty degrees. Each of the individual 840 spacecraft (S) functions as an independent sovereign switch of equal rank which knows the position of its neighbors, and independently handles traffic without ground control. The satellites (S) are capable of transporting calls to millions of customers using portable (P), mobile (M) and fixed (F) residential and business terminals, and gateways (G) to public phone networks. The constellation uses the 20 and 30 GHz frequency bands for communications between Earth and the constellation (C), and the 60 GHz band for communicating among the satellites (S). The present invention is designed to support in excess of 2,000,000 simultaneous connections, representing over 20,000,000 users at typical business usage levels, and over 350 billion minutes of use per year. Only a system such as the preferred embodiment, which utilizes 840 satellites at a preferred minimum mask angle of forty degrees, can accomplish these challenging objectives.

Satellite communication system

Methods and apparatus which route, control and manage traffic throughout a Satellite Communication System operating in low Earth orbit are disclosed. Voice, video and data traffic from terrestrial gateways (G) and from portable (P), mobile (M) or fixed (F) terminals are directed up through the constellation of satellites (S) and back down to destinations on Earth. The satellites provide continuous worldwide communication services while insuring uniform end-to-end transmission delays. The satellite network is highly adaptive to the constantly changing network topology, and will offer a synchronous circuit switched communication service that provides sequential delivery of user data, regardless of the type of the data transmitted. The network employs datagram switching, as opposed to conventional virtual circuit switching techniques. Packets associated with a single phone call do not necessarily travel along the same route, and consequently arrive at their common destinations at different times with a variable transmission delay. Packets (26) received from a portable (P), mobile (M) or fixed (F) terminal, from a satellite (S), or from a stationary gateway (G) are dispatched from an origin node (OUR.sub.-- NODE) to a destination node (DEST.sub.-- NODE) according to address instructions carried in the packet header (28). At each node, propagation delay vectors OUR.sub.-- DELAY.sub.-- EST [DEST.sub.-- NODE, ] are calculated using local computers. These delay vectors estimate a time delay which the packet (26) encounters in traveling from the origin node (OUR.sub.-- NODE) to the destination node (DEST.sub.-- NODE). An optimal route (opt.sub.-- link) is then selected from the set of calculated delay vectors, and the packet (26) is routed to the destination node (DEST.sub.-- NODE) via the pathway (opt.sub.-- link) that insures both the lowest end-to-end delay and the best overall traffic management of the network.

Traffic routing for satellite communication system

The present invention overcomes the limitations encountered by conventional packet switching using virtual circuits. The present invention utilizes a 'datagram' approach that routes every packet (22) conveyed by the system independently at every node in the network. The packets (22) are directed along an optimized pathway through the network by a fast packet switch (38) that directs traffic based on instructions from an adaptive routing processor (12A) that continuously runs an adaptive routing software (12B). This adaptive routing processor (14) supplies an output (12C) to a routing cache memory (20) which stores fast packet switch routing port output tags (30). An input packet processor (28) extracts a supercell address from the header (24) of each packet (22) and uses the supercell address (21A) as an index to retrieve a fast packet switch output port tag (30) stored in the routing cache memory (20). This tag (30) is prepended to the packet (22), and sent to an input port (36) of the fast packet switch (38), which includes a number of multi-stage self-routing switch modules (132) and a number of asynchronous packet multiplexors (134). The modules (132) and multiplexors (134) route the tagged packet (34) to an output port (40) which is connected either to a scanning beam antenna (SBA) or an intersatellite link antenna (ISA).

Non-blocking dynamic fast packet switch for satellite communication

Methods and apparatus which route, control and manage traffic throughout a Satellite Communication System operating in low Earth orbit are disclosed. Voice, video and data traffic from terrestrial gateways (G) and from portable (P), mobile (M) or fixed (F) terminals are directed up through the constellation of satellites (S) and back down to destinations on Earth. The satellites provide continuous worldwide communication services while insuring uniform end-to-end transmission delays. The satellite network is highly adaptive to the constantly changing network topology, and will offer a synchronous circuit switched communication service that provides sequential delivery of user data, regardless of the type of the data transmitted. The network employs datagram switching, as opposed to conventional virtual circuit switching techniques. Packets associated with a single phone call do not necessarily travel along the same route, and consequently arrive at their common destinations at different times with a variable transmission delay. Packets (26) received from a portable (P), mobile (M) or fixed (F) terminal, from a satellite (S), or from a stationary gateway (G) are dispatched from an origin node (OUR.sub.-- NODE) to a destination node (DEST.sub.-- NODE) according to address instructions carried in the packet header (28). At each node, propagation delay vectors OUR.sub.-- DELAY.sub.-- EST �DEST.sub.-- NODE, ! are calculated using local computers. These delay vectors estimate a time delay which the packet (26) encounters in traveling from the origin node (OUR.sub.-- NODE) to the destination node (DEST.sub.-- NODE). An optimal route (opt.sub.-- link) is then selected from the set of calculated delay vectors, and the packet (26) is routed to the destination node (DEST.sub.-- NODE) via the pathway (opt.sub.-- link) that insures both the lowest end-to-end delay and the best overall traffic management of the network.

Growing community of inventors

Palo Alto, CA, United States of America

Moshe L Liron